#include <stdio.h>
#include <stdlib.h>

#define rep(i,n) for (int i=0; i<n; i++)

#define TRACE(x...) 
#define PRINT(x...) TRACE(printf(x))

int hd;
int sol[110];
int n;

int main() {
	scanf("%d", &n);
	hd=1010;

	rep(i,n) scanf("%d", &sol[i]);

	rep(i,n) if (abs(sol[(i+1)%n]-sol[i])<hd) hd = abs(sol[(i+1)%n]-sol[i]);
	PRINT("hd: %d\n", hd);

	rep(i,n) if (abs(sol[(i+1)%n]-sol[i])==hd) {
		printf("%d %d\n", i+1, (i+1)%n+1);
		return 0;	
	}

	return 0;
}
